I have 2002 X5 3.0i that recently had some head work done (overheated). Since then I have had many issues and most have been fixed including the dreaded "trans fail safe". However when I start the car, unless I step on the gas within 1-3 seconds and rev the engine pass 3000 rpm, the engine has no power. If I step on the gas right away and rev it high, the car has full power when I drive it until I turn it off again.
I get the following codes:

DME: VANOS inlet camshaft end position not reached
DME: VANOS exhaust camshaft end position not reached

I am wondering where to start looking. Could it be timing? The next mechanic who looked at it (not the one who did the head work) checked the vanos and told me they were functioning correctly. He seems to think that ECU is malfunctioning because the original mechanic did not connect the wires correctly and shorted parts of the ECU.

Please help.